Family is extremely important in Muslim culture. The family is often extended to three or more generations. There is great stability, coherence, and support in the family. And because the sense of family honor is so high it can cause many difficulties when one member converts outside the Muslim faith.
Seek God for how He would have you pray for Muslim families.
From the 30 Days of Prayer Guide:
“Workers ask our families to pray together for an extended Muslim family. Specifically, that some of you would commit both yourself and your family to pray for a season. As you pray together, expect the Holy Spirit to lead you all into new depths of prayer.”